Recursive digital filter design based on FRM approach

This paper presents a technique for the synthesis of very sharp IIR filter using the frequency response masking (FRM) technique. Both the bandedge shaping and masking filters are recursive filters. The filter is optimized jointly using semi-infinite programming. Bounded input bounded output (BIBO) stability is ensured by imposing constraints on the multiplier coefficients during the optimization process. Design example shows that very sharp robust recursive digital filters with low computational complexity can be obtained.